1. Field of the Invention
The present invention relates to a semiconductor chip module such as multi-chip module and single chip module applicable for the fields of computers and communications the like where high speed signal processing is required.
2. Related Background Art
With the increased demand for large-scale function and high speed operation of electronic devices, logic LSIs have achieved high speed operation, with a delay time per gate of several hundreds picosecond. However, the conventional assembling structure which mounts a large number of dual-in packages (DIPs) or plug-in packages on a printed circuit board has become difficult to bring out performance of high speed LSIs sufficiently. In order to overcome such a problem, a multi-chip module system has been developed and put into practical use, which mounts large number of chips on a single ceramic substrate and can provide high speed performance with high density assembling (refer to "LSI HANDBOOK", the first edition, pp. 415-416, The Institute of Electronics and Communication Engineers of Japan, 1984).
In the conventional type of multi-chip module system which mounts semiconductor chips with face up bonding method and dissipates the heat generated by semiconductor chips toward the substrate side, the heat dissipation has been preventing the performance of the semiconductor chip module from becoming aggravated due to the heat resistance.
It was, however, not possible to obtain adequate heat dissipation by this system. Accordingly, the performance of the semiconductor chip module gradually becomes aggravated, the rate of failure is increased, and it becomes impossible to use the semiconductor chip module over a long term.